Note 80 — Chapter VII · Watt’s Experiments on Steam—Invents the Separate Condenser.

“I have now (April, 1765) almost a certainty of the facturum of the fire-engine, having determined the following particulars: The quantity of steam produced; the ultimatum of the lever engine; the quantity of steam destroyed by the cold of its cylinder; the quantity destroyed in mine; and if there be not some devil in the hedge, mine ought to raise water to 44 feet with the same quantity of steam that theirs does to 32 (supposing my cylinder as thick as theirs), which I think I can demonstrate. I can now make a cylinder 2 feet diameter and 3 feet high, only a 40th of an inch thick, and strong enough to resist the atmosphere; sed tace. In short, I can think of nothing else but this machine.”—Watt to Dr. Lind, quoted in Muirhead’s ‘Life of Watt,’ 94–5.